The Haycock Mountain quadrangle lies in the central part of the Markagunt Plateau in southwest Utah and includes the eastern part of Panguitch Lake, a popular area of summer and winter recreational use. Despite the plateau's relatively simple structure of a gently east-tilted fault block, the quadrangle contains scenic and instructive exposures of south-west Utah's youngest basaltic lava flows, classic examples of inverted valleys capped by older lava flows, and the southern margin of the Markagunt Megabreccia, including newly identified, exceptionally instructive exposures of its basil slip surface. The Megabreccia is the debris of Utah's largest catastrophic landslide deposit, which covers 1300 square miles (3400 kmÄ) of the northern and central Markagunt Plateau.

This CD contains geographic information system (GIS) files in ESRI file geodatabase and shapefile formats. Two plates-a geologic map at 1:24,000 scale and an explanation plate-and a 36-page booklet are also included in PDF format. The latest version of Adobe Reader is required to view the PDF files.